Work machines, in particular forestry equipment and forest machines, e.g. harvesters and forwarders, have an articulated boom and a tool at the tip of the boom. The tool can be e.g. a harvester head, a felling head, a harvesting and processing head, or a log grapple. The tool can be used e.g. to cut standing trees, to process felled trees or to grab objects, such as logs or tree trunks. When using such a tool, it is moved under the control of an operator of the work machine to a desired position mainly by controlling the position of the boom and moving the tool with the boom, and optionally also by moving the work machine. Thereafter, or meanwhile, also the tool itself must be oriented according to the need. The tool is correctly oriented in relation to e.g. a standing tree to be harvested or a log lying on the ground or in a pile.
It has been noticed that turning the tool to a correct orientation takes some time and may be somewhat cumbersome for the operator. Thus, the work machine is not efficiently used and/or not convenient to use. Furthermore, repetitive positioning of the tool during long work periods can cause operator fatigue, which may lead to decreased productivity.